Adopted as a child, new father Mel Colpin (Ben Stiller) decides he cannot name his son until he knows his birth parents, and determines to make a cross-country quest to find them. Accompanied by his wife, Nancy (Patricia Arquette), and an inept yet gorgeous adoption agent, Tina (Tea Leoni), he departs on an epic road trip that quickly devolves into a farce of mistaken identities, wrong turns, and overzealous and love-struck ATF agents (Josh Brolin, Richard Jenkins).